Antidepressants: Common Medications & Side Effects

Antidepressants are medications used to treat depression and certain other mental health conditions. They act on the central nervous system in different ways.

These medications may be prescribed when depression symptoms interfere with daily life and well-being. Symptoms may include persistent sadness, emotional distress, changes in sleep or appetite, fatigue, and feelings of guilt.

A psychiatrist or other qualified healthcare provider can diagnose depression and recommend the most appropriate treatment. The provider will determine whether medication is appropriate, which medication to use, the recommended dose, and how long treatment should continue.

Types of antidepressants

Antidepressants act on chemical messengers in the brain known as neurotransmitters. Depending on the medication, they may increase or modify the activity of neurotransmitters involved in mood regulation.

These medications do not all work in the same way. Antidepressants are therefore divided into classes according to their mechanism of action.

The main types of antidepressants are:

1. Tricyclic antidepressants

Tricyclic antidepressants are an older class of antidepressants. They primarily block the reuptake of norepinephrine and serotonin, increasing the availability of these neurotransmitters in the brain.

Depending on the medication, tricyclic antidepressants may be prescribed for depression, panic disorder, chronic pain, neuropathic pain, narcolepsy, premature ejaculation, or nighttime bed-wetting in children. Some of these uses are off-label, meaning the medication is prescribed for a condition that is not included in its FDA-approved labeling.

Examples: imipramine, clomipramine, amitriptyline, nortriptyline, desipramine, doxepin, protriptyline, and trimipramine.

Side effects: common side effects of tricyclic antidepressants include drowsiness, fatigue, dry mouth, blurred vision, headache, tremors, heart palpitations, constipation, nausea, vomiting, dizziness, flushing, sweating, low blood pressure, and weight gain.

2. Selective serotonin reuptake inhibitors (SSRIs)

Selective serotonin reuptake inhibitors (SSRIs), block the reuptake of serotonin by nerve cells. This increases the availability of serotonin in the brain.

SSRIs are among the most commonly prescribed antidepressants. Because they generally cause fewer side effects than tricyclic antidepressants, they are often considered a first-line treatment for depression.

Depending on the medication, SSRIs may also be prescribed for panic disorder, anxiety disorders, social anxiety disorder, bulimia, obsessive-compulsive disorder (OCD), premenstrual dysphoric disorder (PMDD), or post-traumatic stress disorder (PTSD).

Examples: fluoxetine, paroxetine, citalopram, sertraline, fluvoxamine, and escitalopram.

Side effects: common side effects of SSRIs include diarrhea, nausea, fatigue, headache, insomnia or drowsiness, dizziness, dry mouth, sexual side effects, including delayed ejaculation or difficulty ejaculating.

3. Serotonin-norepinephrine reuptake inhibitors (SNRIs)

Serotonin-norepinephrine reuptake inhibitors (SNRIs), block the reuptake of serotonin and norepinephrine by nerve cells. This increases the availability of these neurotransmitters in the brain.

Some SNRIs may also have a limited effect on dopamine reuptake.

Depending on the medication, SNRIs may be prescribed for depression, generalized anxiety disorder (GAD) social anxiety disorder, fibromyalgia, neuropathic pain, or chronic pain.

Examples: venlafaxine, duloxetine, and desvenlafaxine.

Side effects: common side effects of SNRIs include drowsiness, headache, dizziness, nausea, dry mouth, constipation, and increased sweating.

4. Serotonin modulators

Serotonin modulators affect serotonin transport and certain serotonin receptors in the brain. Their specific actions vary by medication.

These effects increase or modify serotonin activity. Some medications in this group may also influence other neurotransmitter systems, including norepinephrine, dopamine, histamine, acetylcholine, GABA, and glutamate.

These antidepressants are primarily prescribed for major depressive disorder (MDD). Certain medications may also be used off-label for anxiety symptoms, diabetic neuropathy, or chronic pain.

Examples: vortioxetine, nefazodone, and trazodone.

Side effects: common side effects of serotonin modulators include drowsiness, headache, dizziness, fatigue, dry mouth, and nausea.

5. Norepinephrine-dopamine reuptake inhibitors

Norepinephrine-dopamine reuptake inhibitors block the reuptake of norepinephrine and dopamine in the brain. This increases the availability of these neurotransmitters between nerve cells.

Bupropion may be prescribed to treat major depressive disorder (MDD). A specific bupropion product is also FDA-approved to help people quit smoking.

Examples: bupropion.

Side effects: common side effects of bupropion include insomnia, headache, dry mouth, nausea, and vomiting.

6. Atypical antidepressants

Atypical antidepressants do not fit neatly into the other major antidepressant classes. Their effects on neurotransmitters vary by medication.

Mirtazapine affects norepinephrine and serotonin activity and is prescribed for major depressive disorder.

Examples: mirtazapine.

Side effects: common side effects of mirtazapine include increased appetite, weight gain, drowsiness, sedation, headache, and dry mouth.

7. Monoamine oxidase inhibitors (MAOIs)

Monoamine oxidase inhibitors (MAOIs) block monoamine oxidase, an enzyme that breaks down neurotransmitters such as dopamine, serotonin, norepinephrine, and epinephrine. This increases the availability of these substances in the brain.

MAOIs may be prescribed for major depressive disorder when other antidepressants have not adequately relieved symptoms.

Examples: tranylcypromine, phenelzine, selegiline, and isocarboxazid.

Side effects: common side effects of MAOIs include dizziness, headache, dry mouth, nausea, and insomnia.

MAOIs can also cause a dangerous increase in blood pressure when combined with certain medications or foods containing large amounts of tyramine. Examples include aged cheeses and dried, cured, fermented, or processed meats.

Dosing instructions

The recommended dose varies depending on the antidepressant. Some medications are started at a low dose and gradually increased.

Antidepressants do not usually have an immediate effect. It may take several weeks to notice a meaningful improvement in symptoms.

Some side effects may become less severe or go away as treatment continues. Contact the prescribing healthcare provider if side effects are severe, persistent, or difficult to manage, or if symptoms do not improve over time.

Never stop taking an antidepressant or change the dose without first speaking with the prescribing provider. Stopping suddenly can cause withdrawal-like symptoms, and some medications need to be reduced gradually.

If treatment is not effective, the provider may adjust the dose or recommend a different antidepressant.

Avoid recreational drugs during treatment. Ask the prescribing provider whether it is safe to drink alcohol, as alcohol may worsen symptoms, increase side effects, or interfere with treatment.

Antidepressants during pregnancy

Antidepressants should not be automatically stopped or avoided during pregnancy. According to the American College of Obstetricians and Gynecologists (ACOG), medications for mental health conditions should not be withheld or discontinued solely because a person is pregnant or breastfeeding. The potential risks of medication should be weighed against the risks of untreated depression.

A psychiatrist, obstetrician, or other qualified healthcare provider should assess each case individually. Depending on the severity of depression, treatment history, and overall health, treatment may include psychotherapy, medication, or both.

Anyone who is pregnant, planning to become pregnant, or breastfeeding should speak with a healthcare provider before starting, stopping, or changing an antidepressant.

Natural options

Some supplements may help support mood or sleep, but evidence is limited. They should not replace treatment recommended by a healthcare provider.

Products that may be promoted for mood support include:

• 5-HTP: May help with depressive symptoms, but evidence is limited. Doses reported in the original source range from 50 to 300 mg, up to 3 times per day. It may interact dangerously with antidepressants and other serotonin-raising medications.
• Damiana: May help with stress or anxiety, but evidence for depression is insufficient. The original source lists 400 to 800 mg, 3 times per day. It may interact with medications and affect blood sugar.
• St. John's wort: May help some people with mild to moderate depression, although results are mixed. The original source lists up to 300 mg, 3 times per day. It can reduce the effectiveness of many medications and may dangerously increase serotonin when combined with certain antidepressants.
• Melatonin: May improve sleep, but there is limited evidence that it directly improves depression. The original source lists 0.5 to 5 mg before bedtime. It should not replace standard depression treatment.

There are no FDA-approved doses of these products for treating depression. A healthcare provider or pharmacist should be consulted before use.

A balanced diet can support general health during depression treatment. However, eating foods that contain tryptophan, including bananas, tomatoes, walnuts, and avocados, has not been established as a replacement for medical treatment.

Homeopathic products

Some people use homeopathic products alongside conventional depression treatment. However, there is no reliable evidence that homeopathy effectively treats depression or any other health condition, and these products should not replace therapy, antidepressants, or other recommended care.

Homeopathic products traditionally associated with emotional symptoms include:

• Ignatia amara: Traditionally used for symptoms associated with grief, emotional distress, or persistent sadness.

• Pulsatilla: Traditionally used for mood changes, tearfulness, or a desire for reassurance.

• Natrum muriaticum: Traditionally used for sadness, grief, social withdrawal, or low self-esteem.

These descriptions reflect traditional homeopathic practice and do not mean the products have been proven to treat depression. Homeopathic products are not FDA-approved for any use and may not meet modern standards for safety, effectiveness, or quality.

Speak with a healthcare provider before using any homeopathic product, particularly during pregnancy, while breastfeeding, or when taking other medications.